Device for applying new tread material to tires



June 28, 1949. T. P. BACON, JR

DEVICE .FOR APPLYING NEW TREAD MATERIAL TO TIRES 4 Sheets-Sheet 1 Original Filed Dec. 7, 1942 mams PBnca/vJE QTmK/VEY.

June 28, 1949. T. P. B-ACON, JR 2,474,511

DEVICE FOR APPLYING NEW TREAD MATERIAL TO TIRES Original Filed Dec. 7, 1942 4 SheetsSheet '2 7?" 5 43 I 42 o 44 15' Q v II' 46 w 6 5 2 D u; Z4. 2

{Z 34 v m q: I ikl 36 filo/v05 R5000 if I E I June 28, 1949. T..P. BACON; JR 2,474,511

DEVICE FOR APPLYING NEW TREAD MATERIAL T0 TIRES Original Filed Dec. 7, 1942 4 Sh eets,Sheet s T. P. BACON, JR

June 28, 1949;

DEVICE FOR APPLYING NEW TREAD MATERIAL TO TIRES Original Filed Dec. 7, 1942 v 4 Sheets-Sheet 4 ,fu en filo/m5 P5060 5, 05%

Patented June 28 1949 DEVICE FOR APPLYING NEW TREAD MATERIAL TO TIRES Thomas P. Bacon, Jr., Oakland, Calif. Original application December 7, 1942, Serial No.

468,320, now

Patent No. 2,422,652, dated June 24, 1947. Divided and this application May 29, 1945, Serial No. 596,527

Claims. 7 (Cl. 154-9) This invention relates to a device for applyi new tread material to tires. This application is a division of my copending application Serial No. 468,320, filed December 7, 1942 now U. S. Patent No. 2,422,652, issued June 24, 1947, entitled Method for applying new tread material to tires.

An object of the invention is to provide a device whereby new tread material, in the form of so-called camelback, can be so applied to the periphery of a tire that it is spread uniformly and securely across the entire tread width and all around the periphery of the tire, and is held there under suitable tension. The device provides for the applying of the camelback on an inflated tire by suitable rolling action while the tread surface of the tire is flattened to the full width of the camelback at the position where the camelback is applied under pressure, and the device also provides for accurate balancing of the tire before, during and after the application of the new tread material. The result is a tire with semi-cured rubber tread material held all around its tread peripheryunder suitable transverse and circumferential tension, and ready to be suitably cured to form the tread on the tire. This device may be employed in connection with new tires, as well as in retreading or recapping, as the case may be.

Another object of the invention is to provide a device whereby a strip of tread material can be quickly and efficiently attached to the periphery of a tire; the tire being inflated and trul balanced, the camelback being fed tangentially to one portion of the tire periphery at a time while the tire is rotated until the entire periphery of the tire is covered by the camelback; the tread surface of the tire being transversely flattened only where the camelback is tangentially applied to the tire so that the camelback is applied to a flat surface of the tire which is allowed subsequently to expand under the force of inflation, thereby holding the camelback under tension, both transversely and circumferentially; the camelback on the tire thus prepared is thereafter cured in any suitable manner to form the traction surface of the tire.

Another object of the invention is to provide a devic which permits the convenient balancing of the tire so that it is truly balanced when the new tread material is applied to its periphery.

Another object of this invention is to provide a device for applying new tread material to tires which is highly useful and simple in construction. Convenience of arrangement, lightness and comparative inexpense'of manufacture are further objects which have been borne in mind in the production and development of the invention.

Other objects of the invention together with the foregoing will be set forth in the following description of the preferred method, and the preferred embodiment of means for practicing the same, which is illustrated in the drawings accompanying and forming part of the specification. It is to be understood that I do not limit myself to the embodiment disclosed in said description and the drawings as I may adopt variations of my preferred forms within the scope of my invention.

The invention is clearly illustrated in the accompanying drawings, wherein:

Fig. 1 is a cross section of the carcass of the tire, the tread surface of which is conveniently prepared for receiving the new rubber.

Fig. 2 is a sectional view of the tire, showing a smaller strip of new rubber applied to it for the purpose of balancing it.

Fig. 3 is a sectional view of the tire, showing somewhat diagrammatically the flattening of the tire at the point Where the camelback is applied to the periphery under flattening pressure.

'Fig. 4 is a diagrammatic side view, showing the feeding and application of the camelback to the tire periphery.

Fig. 5 is a front view of said apparatus.

Fig. 6 is a side view of an apparatus for balancing the tire and for applying the camelback to the tire.

Fig. 7 is a detailed view of a tire rim on which the tire is supported, showing the balancing and journal devices in the rim.

Fig. 8 is a fragmental view of a modified arrangement of the pressure roller support in my apparatus.

Fig. 9 is a fragmental view of a modified arrangement for the adjustment of the tire relatively to the pressure roller.

Fig. 10 is a modified form of my apparatus.

Fig. 11 is a detail view of the supporting rollers of said modified form, and

Fig. 12 is a fragmental view showing the deflection measuring device on the apparatus.

The herein device is adapted to be used in connection with tires where the accurate balancing of the tires is of importance. Such balancing at the present is particularly important in connection with airplane tires, which by reason of the transverse curvature of their traction surface present the additional problem of applying the new tread material smoothly across the entire traction surface and also all around the tire periphery under mass for the accurate balance of the tire. Then suitable cement is applied to the roughened periphery of the tire. The tire is-provided with the usual inner tube, mounted on a rim-and is inflated. Then camelback is applied at one portion of the tire periphery under such pressure that the tire periphery is transversely-flattened for a substantial flat surfacecontact with the camelback. Then this pressure point is circumferentially shifted on the tire periphery in such a manner as to gradually wrap the camelback around the tire periphery, always keeping the respective portion ofthe tire wherethe camelback is fed to it in flattened condition. The remaining portions ofthe .tire periphery are permitted to assume theirsubstantially normal position under inflation. The camelback isfed substantially tangentially to the'tire periphery and the only portion of the tire periphery which is flattened isthe-place where the camelback is fed thereunto. In 'other'words, at the transverse line where the portion of the camelback first contacts the tire periphery, the contact is made under pressure sufiicient to flatten the tread surface of the tire. The pressure is applied externally upon the camelback and againstthe internal pressure of the tire. The area of flattening isshifted circumferentially around the peripheryof the tire at the rate the'camelback is appliedand the remaining areas of the tire are permitted to. round out under the forceof inflation. After :the camelback is applied all around the tire, the tire is again tested and balancedby additional rubber diametrically opposite the heaviest unbalanced parts.

The illustrative'embodiment of my apparatus herein includes a frame formed by azpair of standards l6 spaced from each .otherwand supported on any suitable'base H. :In .thepresent form, the standards are open frames havingiupwardly converging sides, at the-apexof which is a journal H3 in which is mounted a pressure roller l9 transversely between the frames" l6. Spacedfrom'the journal IE to a distance greater than the largest tire that may be handledin the. apparatus-are knife-edge balancing rails. 2|. "These rails 2| are parallel. There is a rail 32! .in each frame extending substantially .atrightH-angles to the axis of the roller l9. The knife-edge of each of the rails 2| is its upper horizontal edge .sothat a tire with suitable supports may .be balanced thereon. It is to'be noted-that each rail :2l is of sufficient length toallow'considerablev rolling and play of the tire in'theapparatus for the purpose of determining'the'balance of the tire.

A tire 22 is suitably prepared,.and then mounted on a suitable rim 23, which in the presentillustration is a' regular; curing ,'rim: :Of the type having flanges extendingup on the sides of the'tire to about the widest portion: of the tire. Inside of thiscuringrim 23 are providedapair of spiders 24 spaced from eachoth axially with respect to the rim-23. The arms webs of the spiders 24 intersect each other a'tltheaxis of the rim 23. A central hub 26is formed in each of said spiders 24. A shaft 2! extends through the hubs 26 ofthe spiders 24. The outside ends of the 4 arms of the spiders 24 are provided with arcuate shoes 28 which conform to and suitably engage the inner surface of the rim 23. The outer ends of the shaft 21 are formed into balancing pins 29 of comparatively small diameter. The length of the shaft 26 is so related to the distance between the frame members IB that the balancing pins 29 of the shaft 2'! rest and ride upon the upper knife edges of the opposite rails 2l.

The roller l9 may be so mounted in the frames I6 as to be movable under pressure against the topof the tire 22. In the present preferred form, however, means are provided for pushing the tire up against the roller I!) to apply the necessary flattening pressure and also to suitably align and center the tire-with respect to the roller H). For

:this purpose, a pair of spaced pressure rollers "3| are supported on arms 32 transversely of the tire periphery and so spaced as to engage the tire periphery and holdthe tire accurately centered against the top roller l9. The supporting arms 32 for these rollers 3| are pivotally joined to a sliding block 33, which latter in turn is guided in a vertical guide bracket 36 on a path which is in alignment with the center of the roller l9. In this illustration the arms 32 arealso suitably anchored by an adjustable stay 34 whereby the distance between the rollers3l maybe varied. To accomplish the easy movement of the rollers 3! against the tire 22 for lifting the tire 22 and for pressing it against the top roller IS, a foot lever 31 is provided. This foot lever 31 is pivoted on a bracket 38. One end of this lever 37 is pivoted to the sliding block "33. The other end of this foot lever 21 is provided with a suitable'foot pedal 39 so that when the operator stepson the foot pedal 39 that will move the block 33 upwardly, so as to force the rollers 3! against the tire 22. The tire shifts between the rollers 13! until it is properly centered and aligned with-thepressure roller l9. Further pushing down of the'foot pedal 39 exerts the pressure to press the tire 22 against the top roller H) with sufficient force to accomplishthe desired flattening of the portion of the tire which is opposite the roller 19. A releasable latch 4| is provided on the base-l1 and can be swung over the foot lever 37 so as toifasten the foot lever in the depressed position where the tire 22 is flattened against the roller l9. The positions of roller 3! can be changed to accommodate tires of various sizes .by adjusting the length of the stay 34. It is understood, however, that the same adjustment when needed might be performed by other devices such as by looking the lever 31 in various depressed positions corresponding to the diameters of the tires treated.

The camelback 42 is usually supplied in a reel which is journaled or supported on a suitable journal bracket 43. This bracket may be supported ona separate support or the bracket 42 may be extended from the standards -l6 of the apparatus. A guide roller 44 is supported on arms 46 on the standards It so that it is slightly above but parallel with the center line of the roller l9, and guides the camelback 42 from the reel to under the roller l9. Then as either the roller H3 or the tire 22 is rotated, the camelback42 is fed and applied to the periphery of-the tire 22. In the present illustration the tire would berotating during this operation in a-counter-clockwise direction, viewing'Figl 6.

While the rollers 31 normally maybe sufiicient to support a tire in a vertical-position as it is pressed against the pressure rol1erl9, yet in some instances it may be necessary .to prevent the lat- 5; eral tilting of the tire. For this. purpose a guide 50 is extended inwardly from each: side of the frame l6. One of these guides 50- is. suitably ad justable to accommodate tires of various-sizes. as to width. The guides 50 are so spacedthat the opposite sides of the hubor theoppositesides of the tire, as the case may be. are in light sliding engagement therewith so as to permit. the unobstructed lifting and lowering of the tire toward and away from the, top roller 1 Shut prevent sidewise tilting of the tire out of the vertical plane.

In the modified form of the apparatus, shown in Fig. 8, the roller [9 is supportedon sliding journal boxes 5|, each of which travels onathreaded shaft 52. The threaded shafts-are, iournaled in a head 53 on the top of each standard. It and are provided with a suitable handle 54, for facilitatin the adjustment. The'sliding blocks 5i are guided in guide slots 55 in said heads 53. In this device pressure can be applied by evenly adjustin the opposite, journal boXes 5| by the rotation of the shafts 52, and thereby moving the roller lfl against the periphery of the tire 22 with the required blocks 56, each of whichhas a journal seat 57' in its top. The ends of the shaft. 21 are rotatably supported on the seats 51. Each of these sliding blocks 56 is guided between vertical guides 58 suitably supported on transverse. braces 59 on the converging sides. of the standards I6. Through each block 56 extends a screw shaft 6 l, the opposite ends of which are journaled'in their respec tive horizontalv braces 59. A suitable handle 62 on the lower end of the screwwshaft 6| facilitates the turning of the screw shaft ineither direction; When the screw shaft'B-I- is turn-ed; its threaded engagement with the sliding block 56 -will move the sliding block toward, to or away from the roller l9, according to the direction in-which the screw shaft BI is. turned; The slidin blocks 56' are off-setinwardly ofthe transverse balancingrails 2|, which latter in this form'are secured tothe outside of the vertical guides58. When the sliding blocks 56 are lowered to below the level of the top, edges of the balancing rails-21'; then the pins 29 atthe ends of the shaft flare-permitted to rest-and freelyroll upon the knife edges of the rails 2 I. After bal'ancingthe tirethe sliding blocks 56 are raised. by turning the-screw shaft 6| so as tov engage the shaft 21 in said seats 51, therebythe tire 22 is lifted and pressed against the roller l9, For simplicity of illustration, the handle 62 is shown herein for the manual turning of the screw shaft 61-, but other suitable means may be used for rotating thescrew" shaft 6|.

In the operation of the apparatus herein described, the tire '22 is provided-with an inner tube mounted; on. the rim 23 with suitable balancing or journal spiders 24 therein. The tire is: then inflated. The tire 22 is buffed or roughened on its periphery. The tire is then allowed tofreely roll on its balancing pins 29 on the knife edges of the rails 2|. The free rolling of the tire on the rails 2|, which are truly horizontal will indicate the heaviest parts of the tire and then small patches or strips of camelbaok are cemented on the lighter sides of the tire, until the tire is balanced so that it remains stationary in any position upon the rails 2|. Then the inflated tire with cement on its outer periphery, is brought to close proximity of the top roller l9 and the end of the camelback 42 is positioned between the roller 6 m and the peripheryof the the 22. Then the flattening pressure is applied in the mannerheretofore'described so as to flatten the tire against the end of the camelback. 42. Then by rotating the tire, or by rotating the roller I9, the periphery of the tire. 22 is successively brought into pressure contact with the camelback 42 under the roller l9. This operation iscontinued until the entire periphery of. the tire is wrapped-into the strip of camelback 42; Then the camelback 4'2 is suitably cutso that its ends on the-tire are joined. The tire then is again lowered onto the balancing rails 2i" and in the event of any unbalanced portion the. same is: suitably corrected by applying somerubber at points diametrically opposite to the heaviestportions of the tire periphery. The

tirethus prepared is placed in any suitable mold for the curing of the camelback so as to vulcanize the same integrally to the tire periphery into the desired traction surface.

Inthe modified embodiment of my inventionshown;v in Figs. 10 and 11, another form'of support for the tire 22 in the apparatus is provided forv holding thetire in a balanced position. The

; standards I6-in this form are'preferably'supported' on a deeper base 66, in which is a central hydraulic. ram 61: of the usual type. On this ram are supported a pair of lateral arms 68- which extend substantially transversely and on an upward incline between the standards I6. The end of each arm: 68= is forked, the prongs t9 of which extend on an incline into the space between the standard lfi'and toward the respective opposite standards IE" on each side of the tire. In other words, the prongs 69 on each arm 68 are divergent and are on'anupward incline, but the sets of prongs 69 on-the opposite arms 68 converge toward each other. This is accomplished by bending the end of each arm '68 toward the position of the tire 22 betweenthestandards l6; On eachprong 69 is aa-supporting roller 1|. The tire 22 wedges itself between the rollers H, but by reason of thesubstantially. tangential contact of the shoulders or fork support of the tire will maintain the tire in substantially vertical position. The tire is raised andilowered by the raising and lowering of the ram- 61, the pressure in which latter is controlled and" manipulated in any suitable manner not shown.

In this form, I also illustrate a use of the device for determining and marking the deflection line onthe tire 22. Tires are usually so infiatedithat under a specifled'load the tire will be compressed to a given percentage of its height.

In orderto facilitate the inflation of'such tires.

to-the-desired pressure, the percentage of specified deflection is indicated by a circular marking around the tire, and the tire is inflated under a given load to be flattened to the deflection mark' indicatedon'the tire; The marking and measuring of a specified percentage of deflection involved in the past a separate and complicated operation. In my apparatus, I provide a scale 12 which is frictionally held in its adjusted positions in a guide 73 at the apex of one of the standards It in such position that the scale 12 is in registry with and parallel to the vertical diameter of the pressure roller l9 and of the tire 22. The lower end of the scale 12 is bent inwardly to form an indicator M for the rim flange position of the tire 22. Inasmuch as the desired deflection is specified usually in percentages, the marking of the tire is accomplished in my apparatus by quickly calculating the percentage on the scale 72. The tire is first brought into contact with the roller I 9 without compressin it. Then the scale 72 is pushed in its guide 73 to a position where the indicator it is aligned with the rim 23 of the tire. Then a reading is taken on the scale '52 to the lowest point of the roller 59, which shows the expanded height of the tire. Then from that the desired percentage of deflection is calculated and deducted. The normal inflated vertical distance from the rim flange to the supporting surface of the tire is considered in present specifications for airplane tires for landing wheels, as the distance equivalent to 100% deflection. The specifications under a normal load specify a vertical deflection at the proper pressure for said load of 35%. After the 35% of said distance as shown on the scale is determined, the scale 12 is pushed up toward the roller 1 9 so as to deduct this 35% from the scale length below said roller [9, namely, so that the marker it assumes a position with the indicator H 35% above its previous position. Then the tire 22 is pressed against the roller i9 until the rim flange 23 is in alignment with the indicator it, In this last position the tire is compressed to the desired 35% deflection. Then by applying paint, chalk or the like to the shoulder or side of the tire at about the point where it turns to its flattened tread surface at the roller 19, and then by rotating the tire 360, an accurate circular marking is obtained. Finally this marking is covcred with indelible paint or the like and forms the permanent desired deflection marking on the tire.

I claim:

1. In an apparatus for placing a strip of tread material around the traction periphery of a tire, a frame having a space therein for said the in inflated condition, a roller element on the frame disposed transversely outside of the tire periphery, pressin means to exert force to the outside of the tire opposite from said roller element so as to lift said tire toward said roller and press said tire against said strip of tread material under said roller with sufficient force to flatten the portion of the traction surface of the tire at said roller to about the same width as the width of said strip of tread material, and side guides on the frame at the opposite sides of said tire slidably holding said tire at a constant angle to said roller.

2. In an apparatus for wrapping a strip of tread material around the traction periphery of a tire, a frame having a space therein for the inflated tire, a rotatable element on the frame disposed transversely outside of the tire periphery, members outside of the tire adjustable with respect to the frame determining the relative spacing between the tire and said rotatable element, a mechanism whereby force is applied to said members for creating a pressure contact between said rotatable element and said inflated tire so as to transversely flatten the portion of the inflated tire opposite said rotatable element to about the same width as that of the strip of tread material, said strip of tread material being inserted between said rotatable element and the flattened portion of said tire periphery, opposed balancing elements arranged on said frame at about right angles to the axis of the tire, and a balancing extension connected to the hub of the tire and adapted to freely rest on said balancing elements and freely to support the tire thereon when the tire is out of contact with said rotatable element.

3. In an apparatus for wrapping a strip of tread material around the traction periphery of an inflated tire, means to rotatably support said inflated tire, a roller element supported transversely to the periphery of the tire, means to adjust the position of said roller element with respect to said tire and'to press said roller element against the adjacent portion of said tire periphery so as to flatten said portion of the tire periphery to substantially the same width as that of said strip of tread material, and means to guide said strip of tread material endwise between said roller element and said tire.

4. In an apparatus for wrapping a strip of tread material around the traction periphery of an inflated tire, a frame, a rotatable pressure element on the frame, and means to hold the tire in position against said rotatable element, said holding means comprising two pairs of op posed rollers, the rollers in each pair diverging from each other and the opposed pairs of said rollers converging toward the middle of the tire, so as to form forked supports with the rollers tangential to the contacting shoulders and sides of the tire.

5. In an apparatus for wrapping a strip of tread material around the traction periphery of an inflated tire, a frame, a rotatable pressure element on the frame, and means to hold the tire in position against said rotatable element, said holding means comprising two pairs of opposed rollers, the rollers in each pair diverging from each other and the opposed pairs of said rollers converging toward the middle of the tire, so as to form. forked supports with the rollers tangential to the contacting shoulders and sides of the tire, and means to raise and lower said pairs of rollers together.

THOMAS P. BACON, JR.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,009,643 Woock July 30, 1935 2,150,650 Errig Mar. 14, 1939 2,254,588 Breth Sept. 2, 1941 2,276,687 Cleveland et a1. Mar. 17, 1942 

